THE PROBLEMS OF GEOLOGY 599 



of energy upon one or more substances is a geological process. It is 

 rare indeed, if it ever happens, that a single agent works through a 

 single force upon a single substance. Commonly two or more agents 

 are doing work by the expenditure of energy of various kinds at the 

 same time upon more than one material. The processes of geology, 

 therefore, vary in their complexity from the action of a single agent 

 through a single force upon a single substance, to the action of all 

 kinds of agents through all classes of force upon the most diverse 

 combinations of substances. Thus the solution by rain-water of pure 

 calcite is a process. Also erosion, which is the work of all the agents 

 by the expenditure of various kinds of energy upon the most diverse 

 combinations of materials, is called a process. It is plain that the 

 number of processes of geology, comprising as they do all possible 

 combinations of energies, agents, and substances, are beyond number, 

 if indeed they are not infinite. If geology is to be simplified, the 

 processes must be analyzed and classified in terms of energies, agents, 

 and results. Each of the classes of energy and agent should be taken 

 up, and the different kinds of work done by it discussed. For instance, 

 the work of the force of gravitation through gases, liquids, and solids 

 should be analyzed. To some extent this has been attempted, but very 

 imperfectly indeed. And such discussion has scarcely been seriously 

 undertaken for the other forms of energy. Text-books should con- 

 sider each of the classes of energy by itself, the nature of the forces it 

 exerts, the processes through which it works, and the results accom- 

 plished through the various kinds of agents. 



The general work of each of the agents and the results accom- 

 plished should be similarly considered. Not only so, but the work of 

 the different forms that each of the agents takes should be separately 

 treated. Thus, besides considering the work of water generally, 

 the work which it does both running and standing must be treated. 

 The first involves the work of streams; the second, the work of 

 lakes and oceans. This involves the treatment of streams as entities, 

 or, to use a figure of Chamberlin's, as "organisms." The treat- 

 ment of the work of gases should involve the subjects of gases of 

 the atmosphere, gases of the hydrosphere, and gases of the lithos- 

 phere. The treatment of the agents will be more satisfactory in pro- 

 portion as the work done by each of the forms of each of the agents 



